Influenza, which is an illness caused by infecting the respiratory tract with an influenza virus, is common in the winter and is highly infectious and easily spread to all ages, and is also known to particularly afflict the elderly (Treanor J, 2004, N Engl. J Med. 350(3):218-20). Influenza viruses, which are enveloped viruses belonging to the Orthomyxoviridae family and the genome of which consists of eight negative-sense single-stranded RNA (ribonucleic acid) segments, are classified into groups A, B and C, and influenza A viruses are further divided into a number of subtypes depending on HA (hemagglutinin) and NA (neuraminidase) as the major surface proteins. 17 types of HA and 10 types of NA are known so far (Cheung T K and Poon L L 2007, Ann N Y Acad. Sci. 1102:1-25; Tong S, et al. 2012, Proc. Natl. Acad. Sci. U.S.A. 109:4269-4274). Influenza viruses continuously produce variant viruses to thus features that may infect birds, pigs and humans depending on the types thereof and create a variety of gene combinations and mutations due to the genome comprising RNA segments. Treanor J, 2004. N Engl. J Med. 350(3):218-20). Because of such persistent mutations, it is difficult to obtain permanent immunity, and currently, the most effective prevention method is to form immunity appropriate for a particular type annually by inoculating a vaccine against influenza virus, which is predicted to be popular every year.
The influenza virus vaccine, which is currently inoculated every year, is a trivalent or tetravalent vaccine composed of HA of H1 and H3 subtypes of influenza A and one or two kinds of HA of influenza B.
A vaccine against various infectious diseases, including the influenza virus vaccine, may be added with a substance for increasing immunogenicity, and such a substance is referred to as an adjuvant. Examples of adjuvants approved for use on humans may include Alum, composed of aluminum hydroxide and aluminum phosphate, an oil-in-water emulsion MF59, AS03, and AS04, composed of the TLR4 agonist MPL and aluminum hydroxide (Rappuoli R, 2011. Nature Reviews Immunology 11, 11(12):865-72).
In addition thereto, there are many reports on enhancing an immune response by administering an antibody and an antigen together, and many attempts are being made to use the antibody as the adjuvant.
The antibody against influenza A virus, filed by the present applicant, exhibits neutralizing activity against various influenza subtypes, and particularly, the antibody disclosed in Korean Patent Application No. 10-2011-0020061 mainly shows neutralizing activity against phylogenetic group 1 (H1, H2, H5, H9, etc.) and the antibody disclosed in Korean Patent Application No. 10-2012-0107512 mainly shows neutralizing activity against phylogenetic group 2 (H3, H7, etc.). Hence, there has been developed a cocktail formulation, which is configured such that two or more kinds of antibodies are mixed and co-administered to thereby exhibit preventive and therapeutic effects against viruses of Groups 1 and 2, which are likely to become pandemic, as disclosed in Korean Patent Application No. 10-2014-0036601.